The special assembly is called a "span bolster". All 8-axle cars use the same arrangement, even the Lionel 16-wheeler from the postwar era.
I'm mulling over a redesign of these for the WECX 801 Schnabel plans. The wood version seems a little chunky, so I'm looking up additional plans to actually build the car from sheet styrene.
There was someone on the MyLargeScale forums who actually 3D-printed a 1:32 scale WECX 801. I should ask to see his diagrams
---PCJ